The investigator proposes an experimental-theoretical program to investigate the mechanism of a charge transfer in proteins and protein lipid (membrane) systems, DNA, RNA, etc. Small molecule-protein interaction form the overture to many elementary physiological processes at the cellular level. The primary manifestation of these interactions is very frequently either an immediate alteration in the membrane potential or a significant rearrangement in the intraprotein charge distribution. In both cases the transport properties of electrical charge carriers in the protein are supposed to change. Solid state physical measurements on proteins are believed to furnish valuable information regarding charge carrier injection into, and movement in, proteins. Thin protein films may offer a unique opportunity to extend this experimental approach towards proteins which are available only in very small quantities. The most recent work shows that: 1) Only a finite number of sites may exist on the surface of protein molecules through which charges carriers can be preferentially injected (ejected) from (into) the electrode into (from) the protein. Similar considerations may be true for the interprotein charge transfer as well. 2) The number of these charge carrier transfer sites must be relatively small, the (partial) blocking of one or two of them per protein being detectable. 3) The preferential charge carrier transfer sites may not be completely equivalent to each other due to either possible minor differences in their actual composition and structure, or the differences in their positions with respects to the injecting electrode and/or to neighboring proteins and their corresponding charge carrier transfer sites. 4) Primary amine groups are probably essential components in the formation of the preferential charge carrier transfer sites on proteins.